Heretofore, plastic automotive trim strips have been manufactured either by injection molding or by extrusion molding of the part desired to be affixed to the viewing surface of an automotive vehicle. As a general rule, extrusion molding is preferred as it is significantly less expensive than injection molding. However, extrusion molding has certain limitations including the fact that the side edges of the article as extruded will be straight and parallel and the ends of each cut-to-length strip will show the cross sectional interior of the extruded material unless such ends are reworked or have separately molded end caps applied.
Additionally, certain parts such as those for trim around the wheel wells have more complex shapes and are typically formed by injection molding.
A method of extrusion molding and automotive trim strip is disclosed in U.S. Pat. No. 4,722,818. Under such patent, the trim strip is made by extruding a thermoplastic material through an extrusion passageway, passing a film strip through a guide passageway in a novel die assembly and then bonding the film strip and the thermoplastic material into engagement.
U.S. Pat. No. 4,719,067 discloses a method of forming an end piece by injection molding onto a previously formed trim strip.
U.S. Pat. No. 4,489,019 discloses a method for producing longitudinal moldings with non-uniform sections without the use of an injection molding machine. Under the invention disclosed therein, one part of the molding is formed by extrusion molding and another part is remolded or reshaped to the desired cross-sectional configuration. U.S. Pat. No. 4,489,019 discloses another method for forming a molding in part by extrusion molding and in part by remolding or reshaping.
It is the object of the present invention to provide a new and noval method and apparatus for molding plastic articles.
It is a further object of the present invention to form a new and molded plastic trim strip.
It is yet another object of the present invention to provide a method and apparatus for molding plastic trim strips and other plastic articles such that shapes not attainable with extrusion molding may be molded at a cost significantly lower than the cost of injection molding a similar part.